Various electrophysiology techniques have been developed for collecting electrophysiology data for a patient. Direct measurement techniques typically involve placing one or more electrodes into contact with biological tissue. For example, an electrophysiology catheter or probe contains one or more electrodes at its distal end, each electrode being able to record electrical activity at the location of said electrode. Thus, by placing the catheter at a particular location relative to a patient's organ, such as the heart, organ-specific electrical activity can be recorded. Signal processing, such as band-pass filtering, can be applied on any such signal to remove noise or otherwise enhance the recorded activity.
As a further example, catheters come in a variety of shapes and with a different number of electrodes (2, 4, 8 etc). Linear catheters are typically used to inspect the progression of the depolarization wave along the anatomy, and they are typically placed in well defined locations: The high right atrial (HRA) catheter monitors the progression of depolarization as it (typically) emanates from the sinoatrial (SA) node; the His catheter monitors progression of depolarization from the atria to the ventricles (typically through the His bundle); etc. A circular multipolar catheter may be placed proximal to or around a pulmonary vein to measure depolarization emanating from the pulmonary vein. Multi-electrode basket catheters may be placed in a chamber, and wholesale collect a plurality of data.
Electroanatomic electrophysiology mapping is a method by which acquired electrophysiology data is spatially depicted on a representation of an organ or body surface, which representation may be referred to as an “Electroanatomic Map”. Examples of Electroanatomic Maps include the spatial depiction of cardiac activation time (also referred to as an isochrone map) or potential distribution on the cardiac surface, possibly as a function of time (potential map). Electroanatomic maps may also depict derived quantities, such as frequency domain analysis (e.g., dominant frequency distributions), cycle length maps, complex fractionated atrial electrogram (CFAE) distributions, regularity index distributions, as well as spatial correlation measures in either the time or frequency domain.